1. Field of the Invention
The present invention relates to a data display unit mounted on a bicycle by which running data such as the running speed, the running time, the running distance etc. of a bicycle are calculated and displayed.
Particularly, the present invention relates to an improvement in the manner of display in a data display unit for a bicycle in which a microcomputer is incorporated to process the input data supplied from a sensor so that determined data such as the running speed etc. may be displayed.
2. Description of the Prior Art
A data display unit for a bicycle for making display of running data such as the running speed, the running distance and the like generally comprises a revolution detecting sensor for detecting the number of revolutions of a wheel and a main body of the display unit for calculating the running speed, the running distance and the like based on a signal from the revolution detecting sensor.
A revolution detecting sensor in general was, in the past, connected to a main body of a display unit by a release wire and the like so that a rotating block provided in the sensor may be mechanically rotated directly by the wheels. However, recently, in order that load may not be applied to a driving system of a bicycle and that the number of revolutions may be detected more accurately, a so-called magnet sensor or a photoelectronic sensor has been utilized as a revolution detecting sensor.
In the U.S. Pat. No. 4,074,196 for example, it is disclosed that a sensor comprising a photoelectronic sensor, a magnetic sensor or a Hall device can be utilized as a revolution detecting sensor. The U.S. Pat. No. 4,156,190 discloses an example of a photosensor as a revolution detecting sensor. These revolution detecting sensors are attached in association with the wheels.
A main body of a display unit having close relation with the present invention is disclosed for example in the U.S. Pat. No. 4,007,419 which comprises a circuit for calculating the running speed, the running distance and the like based on a revolution signal provided from a revolution detecting sensor and also comprises liquid crystal display for indicating the running speed, the running distance and the like. Such a main body of a data display unit is mounted on a desired position near the handle or any other suitable position where the rider of the bicycle can easily see the display.
The running data displayed in a display unit, generally, are mostly numeric data such as running distance and the like. For display of numeric data, it is necessary to satisfy various conditions imposed in connection with a speed unit indication as to where a decimal point is to be positioned, what extent of precision is needed for display, how many figures are needed to the left of a decimal point, and the like.
On the other hand, considering the restrictions on the size of a display panel included in a display unit as well as on the production cost, a large increase of the number of figures cannot be expected.
In these contexts, it cannot be said that such conventional display units have the satisfactory manners of display.